Ablation of the interior lining of a body organ is a procedure which involves heating the organ lining to temperatures which destroy the cells of the lining, coagulate blood and/or denature tissue proteins. Existing methods for the energy transfer as part of effecting ablation include circulation of heated fluid inside the organ (either directly or inside a balloon), laser treatment of the organ lining, microwave heating of the tissue, high power ultrasound heating of the tissue or resistive heating using application of radiofrequency (RF) energy to the tissue to be ablated. These ablation procedures, however, are often carried out without direct endoscopic visualization. For example, ablation of the uterine lining or endometrium typically involves insertion of an elongate ablation device into the patient's cervix without the use of a hysteroscope. However, the thickness of the uterine wall may vary from patient-to-patient depending on a number of factors, such as the phase of the menstrual cycle and anatomical variability in the patient.
Consequently, the ablation depth and ablation profile are usually done by assumption since little data are available to help guide the physician as to how deep the tissue ablation needs to go. It is also difficult for a physician to find out when ablation has been carried out to a desired depth within the tissue during the procedure. Thus, in some instances, too much or too little tissue may be ablated during an ablation procedure.